It does not matter what console you're on I believe. You just set up your social club account, link it to your XBL or PSN account, join the crew and then when we play online it looks like we can do crew sessions or just play together. It will match you up with people on XBL or PSN, whatever you're on.

PS - As expected, GTA Online has been having massive issues with their servers and not allowing online play. We'll see how much better it gets over the next couple days.